﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using ICSharpCode.SharpZipLib;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.Checksum;

namespace Geek7Utils
{
    /// <summary>
    /// 适用与ZIP压缩
    /// </summary>
    public class ZipHelper
    {
        #region 压缩指定文件 但不需要保存到本地
        /// <summary>
        /// 功能：压缩文件 
        /// </summary>
        /// <param name="file">指定文件</param>
        /// <param name="buffer">压缩文件的字节流</param>
        /// <returns>是否压缩成功</returns>
        public static bool ZipFile(string file, string zipName, out byte[] buffer)
        {
            try
            {
                byte[] byteArray = File.ReadAllBytes(file);

                MemoryStream ms = new MemoryStream();

                using (ZipOutputStream zips = new ZipOutputStream(ms))
                {
                    zips.SetLevel(9); // 0 - store only to 9 - means best compression

                    var entry = new ZipEntry(zipName);
                    entry.DateTime = DateTime.Now;
                    zips.PutNextEntry(entry);
                    zips.Write(byteArray, 0, byteArray.Length);
                    zips.Finish();
                }

                buffer = ms.ToArray(); //这里是一个zip压缩的文件流
                return true;

            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        #endregion

        #region 解压
        /// <summary>
        /// 功能：解压zip格式的文件。
        /// </summary>
        /// <param name="zipFilePath">压缩文件路径</param>
        /// <param name="unZipDir">解压文件存放路径,为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹</param>
        /// <param name="err">出错信息</param>
        /// <returns>解压是否成功</returns>
        public static bool UnZipFile(string zipFilePath, string unZipDir)
        {
            try
            {
                //解压文件夹为空时默认与压缩文件同一级目录下，跟压缩文件同名的文件夹
                if (unZipDir == string.Empty)
                    unZipDir = zipFilePath.Replace(Path.GetFileName(zipFilePath), Path.GetFileNameWithoutExtension(zipFilePath));
                if (!unZipDir.EndsWith("//"))
                    unZipDir += "//";
                if (!Directory.Exists(unZipDir))
                    Directory.CreateDirectory(unZipDir);

                using (ZipInputStream s = new ZipInputStream(File.OpenRead(zipFilePath)))
                {

                    ZipEntry theEntry;
                    while ((theEntry = s.GetNextEntry()) != null)
                    {
                        string directoryName = Path.GetDirectoryName(theEntry.Name);
                        string fileName = Path.GetFileName(theEntry.Name);
                        if (directoryName.Length > 0)
                        {
                            Directory.CreateDirectory(unZipDir + directoryName);
                        }
                        if (!directoryName.EndsWith("//"))
                            directoryName += "//";
                        if (fileName != String.Empty)
                        {
                            using (FileStream streamWriter = File.Create(unZipDir + theEntry.Name))
                            {

                                int size = 2048;
                                byte[] data = new byte[2048];
                                while (true)
                                {
                                    size = s.Read(data, 0, data.Length);
                                    if (size > 0)
                                    {
                                        streamWriter.Write(data, 0, size);
                                    }
                                    else
                                    {
                                        break;
                                    }
                                }
                            }
                        }
                    }//while
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex);
                return false;
            }
            return true;
        }//解压结束
        #endregion

    }
}